Question

How do you verify the identity `tan(u/2)=cscu-cotu`?

Answer 1

See below.

Explanation:

`tan(u/2)=(1-cosu)/sinu` (Identity)

`(1-cosu)/sinu= 1/sinu - cosu/sinu`

`1/sinu=cscu`

`- cosu/sinu= -cotu`

`:.`

LHS

`cscu-cotu`

`LHS-=RHS`